Cementing a wellbore casing

ABSTRACT

A method of cementing a casing in a wellbore includes lowering the casing in the wellbore. The casing includes multiple pipes each of progressively smaller diameters, and a transition point where a first pipe overlaps a second pipe. The method also includes flowing cement into the casing and deploying, by fluidic pressure, a wiper plug assembly in the casing upstream of the cement to push downhole the cement with the wiper plug assembly. The wiper plug assembly includes a hollow wiper plug and a solid wiper plug releasably coupled to the hollow wiper plug. The deploying includes applying fluidic pressure until the hollow wiper plug reaches and is retained at the transition point and the solid wiper plug is released from the hollow wiper plug to flow downhole in the casing to a downhole end of the casing and push the cement out of the casing.

FIELD OF THE DISCLOSURE

This disclosure relates to wellbore operations, and more particularly to wellbore cementing operations.

BACKGROUND OF THE DISCLOSURE

Wellbore cementing is the process of introducing cement to the annulus between the outer surface of a casing and the wall of a wellbore. Casings consist of successive casing pipes or strings extending from a surface of the wellbore to a downhole end of the wellbore. Casings can be steel pipes that protect and support the wellbore. The cement holds the casing in place and forms an additional layer of protection between the casing and the wellbore. The process of cementing a wellbore can be lengthy and expensive. Methods and equipment for improving cementing operations are sought.

SUMMARY

Implementations of the present disclosure include a method of cementing a casing in a wellbore. The method includes lowering the casing in the wellbore. The casing includes multiple pipes each of progressively smaller diameters. The casing includes a transition point where a first pipe of the pipes overlaps a second pipe that extends beyond the first pipe. The first pipe defines a first inner diameter and the second pipe that is carried by the first pipe defines a second inner diameter smaller than the first inner diameter. The method also includes flowing cement into the casing. The method also includes deploying, by fluidic pressure of a fluid, a wiper plug assembly in the casing upstream of the cement to push downhole the cement with the wiper plug assembly. The wiper plug assembly includes: i) a hollow wiper plug that allows the fluid to flow across the hollow wiper plug, and ii) a solid wiper plug releasably coupled to the hollow wiper plug and configured to separate the cement from the fluid. The deploying includes applying fluidic pressure until the hollow wiper plug reaches and is retained at the transition point and the solid wiper plug is released, under fluidic pressure, from the hollow wiper plug to flow downhole in the casing to a downhole end of the casing and push the cement out of the casing.

In some implementation, the deploying includes cementing the wellbore in one trip by pushing, under fluidic pressure of the fluid, a last portion of the cement out of the casing into an annulus of the wellbore as the solid wiper plug travels along a last pipe of the casing to a downhole end of the last pipe where the solid wiper plug is retained.

In some implementations, the deploying includes pushing the last portion of the cement as the solid wiper plug fluidly isolates the last portion of the cement from the fluid in the last pipe. In some implementations, second pipe is the last pipe of the multiple pipes.

In some implementations, the hollow wiper plug includes a first wiper that wipes the first pipe and the solid wiper plug includes a last wiper that wipes a last pipe of the multiple pipes. The method further includes wiping, with the wiper plug assembly pushing the cement, the casing. In some implementations, the last wiper includes an outer diameter smaller than an outer diameter of the first wiper, and the wiping includes wiping the first pipe with the first wiper and wiping the last pipe with the last wiper.

In some implementations, the wiper plug assembly further includes an intermediate hollow wiper plug disposed between and releasably coupled to the hollow wiper plug and the solid wiper plug. The casing includes a second transition point where the second pipe overlaps a third pipe of the plurality of pipes that extends beyond the second pipe. The deploying includes applying fluidic pressure until the hollow wiper plug is retained at the transition point and the intermediate hollow wiper plug is released, with the solid wiper plug coupled to the intermediate hollow wiper plug, from the hollow wiper plug, and deploying further includes applying fluidic pressure until the intermediate hollow wiper plug is retained at the second transition point and the solid wiper plug is released, under fluidic pressure, from the intermediate hollow wiper plug.

In some implementations, first pipe is a surface pipe that extends from or near a terranean surface of the wellbore. Lowering the casing includes setting the first pipe on or near the terranean surface of the wellbore with the second pipe suspending from the first pipe.

Implementations of the present disclosure also include a method that includes flowing cement into a casing. The casing is disposed within a wellbore and includes a first pipe and a second pipe carried by and extending downhole from the first pipe. The first pipe defines a first inner diameter and the second pipe defines a second inner diameter smaller than the first inner diameter. The method also includes deploying, under fluidic pressure of a fluid, a wiper plug assembly in the casing and upstream of the cement to push the cement out of the casing. The wiper plug assembly includes a first wiper plug and a second wiper plug releasably coupled to the first wiper plug. The first wiper plug allows fluid to flow across the first wiper plug and the second wiper plug configured to fluidly isolate the cement from the fluid in the casing. The deploying includes applying fluidic pressure until the first wiper plug reaches and is retained at an inlet of the second pipe. Continuing to apply pressure causes the second wiper plug to be released, under fluidic pressure, from the first wiper plug to flow downhole in the casing to a downhole end of the casing and push the cement out of the casing.

In some implementations, the deploying includes pushing, under fluidic pressure of the fluid, a last portion of the cement out of the casing into an annulus of the wellbore as the second wiper plug travels along a last pipe of the casing to a downhole end of the last pipe where the second wiper plug is retained. In some implementations, the first wiper plug includes a first annular wiper configured to wipe the first pipe and the second wiper plug includes a second annular wiper configured to wipe the last pipe. The method further includes wiping, with the wiper plug assembly pushing the cement, the first pipe and the last pipe.

In some implementations, the second annular wiper includes an outer diameter smaller than an outer diameter of the first annular wiper. The wiping includes wiping from cement the first pipe with only the first annular wiper and wiping the last pipe with only the second annular wiper.

In some implementations, the wiper plug assembly further includes an intermediate hollow wiper plug disposed between and releasably coupled to the first wiper plug and the second wiper plug. The casing includes a third pipe carried by and extending downhole of the second pipe. The deploying includes applying fluidic pressure until the hollow wiper plug is retained at the inlet of the second pipe and the intermediate hollow wiper plug is released, with the second wiper plug coupled to the intermediate hollow wiper plug, from the first wiper plug. The deploying further includes applying fluidic pressure until the intermediate hollow wiper plug is retained at an inlet of the third pipe and the second wiper plug is released, under fluidic pressure, from the intermediate hollow wiper plug.

Implementations of the present disclosure also include a cementing wiper plug assembly that includes a first wiper plug and a second wiper plug. The first wiper plug defines a bore configured to direct fluid from an inlet to an outlet of the first wiper plug. The second wiper plug is releasably coupled to the first wiper plug. The second wiper plug includes a solid body configured to fluidly isolate, when disposed within a casing of a wellbore, a first portion of the casing downhole of the wiper plug assembly from a second portion of the casing uphole of the wiper plug assembly. The casing includes a first pipe and a second pipe carried by and extending downhole from the first pipe. The first pipe defines a first inner diameter and the second pipe defines a second inner diameter smaller than the first inner diameter. The first and second wiper plugs are configured to flow together to an inlet of the second pipe and the second wiper plug is arranged to be released, under fluidic pressure, from the first wiper plug to flow downhole in the casing to a downhole end of the casing and push cement out of the casing, with the first wiper plug retained at the inlet of the second pipe.

In some implementations, the solid body of the second wiper plug sits and is retained at a downhole end of a last pipe of the casing.

In some implementations, the second wiper plug is releasably attached, by a joint that includes a shear pin, to the first wiper plug. In some implementations, one of the first wiper plug or second wiper plug includes a first inner tube that includes an aperture and is inserted into a second inner tube of the other one of the first wiper plug or second wiper plug. The second inner tube includes a shear pin inserted, with the first wiper plug and second wiper plug attached to each other, into the aperture of the first inner tube.

In some implementations, the first wiper plug includes a first annular wiper configured to wipe the first pipe and the second wiper plug includes a second annular wiper configured to wipe a last pipe of the casing. In some implementations, the second annular wiper includes an outer diameter smaller than an outer diameter of the first annular wiper.

The cementing wiper plug assembly of claim 14, further including an intermediate wiper plu. The intermediate plug defines a second bore that directs fluid from an inlet to an outlet of the intermediate wiper plug. The intermediate wiper plug is disposed between and is releasably coupled to the first wiper plug and the second wiper plug. The casing includes a third pipe carried by and extending downhole of the second pip. The cementing wiper plug assembly flows to the inlet of the second pipe and the intermediate wiper plug is arranged to be released, with the second wiper plug attached to the intermediate wiper plug, from the first wiper plug to flow downhole in the casing to an inlet of the third pipe. The second wiper plug is arranged to be released, under fluidic pressure, from the intermediate wiper plug to flow downhole in the casing to an outlet of the casing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front schematic view, partially cross-sectional, of a wellbore during a cementing operation according to implementations of the present disclosure.

FIG. 2 is a front schematic view, cross-sectional, of a multi-stage wiper plug assembly, assembled.

FIG. 3 is a front schematic view, cross-sectional, of the multi-stage wiper plug assembly in FIG. 2 , disassembled.

FIGS. 4-7 are front schematic views, partially cross-sectional, of sequential steps of a method of cementing a wellbore.

FIGS. 8A-8B are front schematic views, partially cross-sectional, of sequential steps of setting a wiper plug on a setting profile.

FIG. 9 is a flow chart of method of cementing a wellbore according to a first implementation of the present disclosure.

FIG. 10 is a flow chart of method of cementing a wellbore according to a second implementation of the present disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

The present disclosure relates to equipment and methods for cementing a wellbore quickly and without having to cement and drill in stages to cement a progressive casing. Typically, to case and cement a wellbore, multiple casing pipes are lowered and cemented in separate trips, which requires lengthy rig time and can be costly. The present disclosure includes a multi-stage wiper plug assembly with multiple wiper plugs that are releasably attached to each other. The wiper plugs are released one at a time each instance in which the diameter of the casing is reduced. Each wiper plug corresponds with a respective pipe of the tapered casing so that each wiper plug is released at the beginning of its respective pipe to wipe its respective pipe.

Particular implementations of the subject matter described in this specification can be implemented so as to realize one or more of the following advantages. For example, the multi-stage wiper plug of the present disclosure allows running and cementing tapered casing in a single trip, which can reduce the time and cost required to cement a casing compared to traditional cementing methods. Additionally, cementing errors can be reduced by running the casing in one trip and cementing the casing in one operation. Moreover, implementations of the present disclosure can eliminate multiple tripping in and out of hole and cementing jobs. This process can save rig time and cost and can ensure faster milling operation. Additionally, implementations of the present disclosure allow the quick lowering of casing, which can eliminate or reduce caving in the wellbore.

FIG. 1 shows a wellbore 102 formed in a geologic formation 101. The geologic formation 101 can include a hydrocarbon reservoir from which hydrocarbons can be extracted. The wellbore 102 extends from a surface 108 (e.g., a terranean surface) of the wellbore to an end or outlet 115 of the casing 104 at or near a bottom hole end 107 of the wellbore 102.

The wellbore 102 includes a casing 104. The casing 104 includes multiple pipes of progressively smaller diameter, each assembled on location. For instance, the pipes of the casing can be assembled on the rig floor before running in hole. The surface equipment 116 that lowers the piping can be a rig, a platform, a truck, or similar equipment.

The casing 104 is cemented with a cement “C” in one operation using a multi-stage wiper plug 106. For example, as further described in detail below with respect to FIGS. 4-7 , the casing 104 is cemented by first flowing cement “C” into a bore of the casing 104. Then, the multi-stage wiper plug 106 is deployed by applying fluidic pressure of a fluid “F” (e.g., drilling mud). The fluidic pressure pushes the wiper plug assembly 106 and the wiper plug assembly 106 pushes the cement “C” downhole. The wiper plug assembly 106 has individual wiper plugs that separate in stages to reach the end 115 of the casing and push the cement “C” completely out of the casing into an annulus 112 of the wellbore 102. The annulus 112 is defined between an outer wall of the casing 104 and the wall of the wellbore 102.

FIG. 2 depicts the assembled multi-stage wiper plug assembly 106. FIG. 3 depicts the multi-stage wiper plug assembly 106, disassembled. Referring to FIGS. 2 and 3 , the multi-stage wiper plug assembly 106 includes multiple individual wiper plugs 110 a, 110 b, 110 c. For example, the multi-stage wiper plug assembly 106 includes a first wiper plug 110 a, a last (or second) wiper plug 110 c, and an intermediate wiper plug 110 b disposed between the first and last wiper plugs 110 a, 110 c. In some implementations, the multi-stage wiper plug assembly 106 includes two, three, four, five, or more wiper plugs, depending on the number of pipes of different diameters in the casing to be cemented.

The first wiper plug 110 a defines a bore 218 that allows fluid “F” to flow across the first wiper plug 110 a. For example, the first wiper plug 110 a can be a hollow wiper plug. The first wiper plug 110 a directs fluid “F” from an inlet 211 of the first wiper plug 110 a to an outlet 213 of the first wiper plug. The first wiper plug 110 a has an annular wiper or a group of annular wipers 111 a that wipe the first pipe of the casing. The annular wipers 111 a are attached to a tubular body 202 of the first wiper plug 110 a.

The intermediate wiper plug 110 b (e.g., a second hollow wiper plug) is similar to the first wiper plug 110 a in that it also allows fluid to flow across its body. For example, the intermediate wiper plug 110 b has a bore 219 that directs the fluid “F” from an inlet of the intermediate wiper plug 110 b to an outlet of the intermediate wiper plug 110 b. The intermediate wiper plug 110 b has an annular wiper or a group of annular wipers 111 b that wipe the pipe that follows the first pipe of the casing. The annular wipers 111 b are attached to a tubular body 204 of the intermediate wiper plug 110 b.

The last or leading wiper plug 110 c does not allow fluid “F” to flow across its body. For example, the last wiper plug 110 c can have a bore 215 with a closed end 217 (e.g., a cap or plug) that prevents fluid from flowing across the last wiper plug 110 c. In some implementations, the last wiper plug 110 c can be a solid wiper plug that has no bore. The last wiper plug 110 c also has a body 206 and annular wipers 111 c that extend from the body 206. The wipers 111 c wipe the bore of the last pipe of the casing.

The last wiper plug 110 c thus fluidly isolates or separates, when disposed within the casing of the wellbore, a first portion of the casing downhole of the wiper plug 106 assembly from a second portion of the casing uphole of the wiper plug assembly 106. For example, the last wiper plug 110 c does not allow the fluid “F” to flow across the wiper plug assembly 106 to mix with the cement that is downhole of the wiper plug assembly 106.

The wiper plugs 110 a, 110 b, 110 c are releasably coupled to each other. For example, the intermediate wiper plug 110 b is releasably attached to the first wiper plug 110 ca, and the last wiper plug 110 c is releasably attached to the intermediate wiper plug 110 b. The inlet of the intermediate wiper plug 110 b can be attached to the outlet 213 of the first wiper plug 110 a.

The wiper plugs 110 a, 110 b, 110 c can be attached with a releasable joint 210, 220 such as a snap latch or a shear pin joint. For example, the intermediate wiper plug 110 b can be attached to the first wiper plug 110 with a shear pin 216. The shear pin 216 breaks under fluidic pressure that pushes the intermediate wiper plug 110 b away from the first wiper plug 110 a. In some implementations, the first wiper plug 110 a can form male-female connection with the intermediate wiper plug 110 b. For example, the first inner tube 110 a has a first inner tube 212 that has one or more apertures 223. The first inner tube 212 is inserted into a second inner tube 214 of the intermediate wiper plug 110 b. The second inner tube 214 has a shear pin 216 inserted, with the first wiper plug 110 a and the intermediate wiper plug 110 b attached, into the hole 223 of the first inner tube 212. In some implementations, the first wiper plug 110 a can have the female connection and the intermediate wiper plug 110 b can have the male connection. Additionally, the two wiper plugs can be attached to each other by a shear pin without the tubes 212, 214, or by any other releasable means such as a releasable latch, or a ball and seat-activated joint.

The second joint 220 between the last wiper plug 110 c and the intermediate wiper plug 110 b can be similar or the same as the first joint 210 between the first wiper plug 110 a and the intermediate wiper plug 110 b. For example, second joint 220 includes an inner tube 222 of the intermediate wiper plug 110 b inserted into an inner tube of the last wiper plug 110 c, with a shear pin 226 connecting the two tubes.

The joints 210, 220 can be progressively stronger from the first to the last to allow the wiper plugs to be separated one by one in order. For example, the shear pins 216, 226 can be progressively stronger such that the first (weakest) shear pin 216 breaks under a shear force smaller than a shear force required to break the following shear pin 226, and so on. The last pin 226 can be the strongest of all the shear pins.

As shown in FIG. 3 , the annular wipers 111 a, 111 b, 111 c can be progressively smaller in diameter such that the first wiper 111 a is the largest and the last wiper 111 c is the smallest. For example, the wiper 111 a of the first wiper plug 110 a has a first outer diameter “D1.” The wiper 111 b of the intermediate wiper plug 110 b can have a second outer diameter “D2” smaller than the first outer diameter “D1.” The wiper 111 c of the last wiper plug 110 c can have a third outer diameter “D3” that is smaller than the second outer diameter “D2.” The outer diameters of the bodies of the wiper plugs can also be progressively smaller.

FIGS. 4-7 are front schematic views of sequential steps of a method of cementing the wellbore 102. As shown in FIG. 4 , the process of cementing the wellbore 102 includes first lowering the progressive or tapered casing 104 into the wellbore in a downhole direction “d.” The casing 104 has two or more pipes of different diameters. The pipes can be assembled at the surface of the wellbore 102.

The casing 104 shown in FIG. 4 has at least three pipes 402, 404, and 406. For example, the first pipe 402 can be the surface casing, the second pipe 404 can be the intermediate casing, and the last pipe 406 can be the production casing. The casing is progressively smaller (in diameter such that the first pipe 402 is the largest (e.g., widest) pipe and the last pipe 406 is the smallest (e.g., the narrowest pipe). Thus, the casing is “telescopically arranged.” For example, the first pipe 402 has a first inner diameter “d1,” the second pipe 404 has a second inner diameter “d2” smaller than the first inner diameter “d1,” and the last pipe 406 has a third inner diameter “d3” that is smaller than the second inner diameter “d2.” For example, the last pipe 406 can be a 5.5-inch pipe, the intermediate pipe 404 can be a 7-inch pipe, and the first pipe can be a 9⅝-inch pipe.

The second pipe 404 can be carried by the first pipe 402 and extends downhole from the first pipe 402. For example, the second pipe 404 can be inserted into and mechanically attached (e.g., threadedly attached) to an end of the first pipe 402. Similarly, the last pipe 406 is inserted into and mechanically attached to the end of the second pipe 404.

The casing 104 has one or more transition points or setting profiles 430, 432. The transition points 430, 432 can be the points of the casing where a pipe overlaps the following pipe that extends beyond the first pipe. In other words, the transition points can be the points where the casing changes in diameter due to a transition of one pipe to the other. In the first transition point 430, the second pipe 404 is disposed inside the outlet 440 of the first pipe 402 so that the first pipe 402 overlaps the second pipe 404. The inlet 444 of the second pipe 404 is disposed inside the first pipe 402. The rim 442 of the inlet 444 of the second pipe 404 forms a sit, shoulder, or a setting profile where the first wiper plug 110 a sits. In some implementations, the transition point can include a collar or a different part where the first wiper plug 110 a sits. The second transition point 432 is similar to the first transition point 430.

As shown in FIG. 4 , during a cementing operation, after lowering the casing 104, cement “C” is flown downhole in the casing 104. Then, the wiper plug assembly 106 is deployed within the casing 104 upstream of the cement “C.” The wiper plug assembly 106 is pushed downhole under fluidic pressure of the fluid “F,” which in turn pushes the cement “C” to the outlet 115 of the casing and into the annulus 112. For example, the fluid “F” exerts fluid pressure on the internal surface of the closed end 217 of the leading wiper plug 110 c and on the annular wiper of the trailing wiper plug. In the first pipe 402, the first wiper plug 110 a ‘wipes’ the bore of the first pipe 402 and pushes the cement “C” toward the outlet 115 of the casing 104.

The annular wipers of the first wiper plug 110 a can have an outer diameter that corresponds with the inner diameter of the first pipe 402. For example, the annular wiper of the first wiper plug 110 a can have an outer diameter that is equal to or greater than the inner diameter of the first pipe 402. Similarly, the annular wipers of the intermediate wiper plug 110 b correspond with the second pipe 404, and the annular wipers of the last wiper plug 110 c correspond with the inner diameter of the last pipe 404.

As shown in FIG. 5 , the wiper plug assembly 106 is flown or deployed until it reaches the first transition point 430. The wiper plug assembly 106 is flown to the first transition point 430 with all of the wiper plugs together. At the first transition point 430, the first wiper plug 110 a sits and is retained at the inlet of the second pipe 404. Thus, the first wiper plug 420 is prevented from flowing along the second pipe 404. At the transition point 430, the intermediate wiper plug 110 b detaches, under fluidic pressure, from the first wiper plug 110 a. The intermediate wiper plug 110 b is released from the first wiper plug 110 a when the joint (e.g., the shear pin of the joint) is broken under fluid pressure of the fluid “F” pushing the intermediate wiper plug 110 b away from the first wiper plug 110 a.

The intermediate wiper plug 110 b remains attached to the last wiper plug 110 c and any other wiper plugs residing between the intermediate wiper plug 110 b and the last wiper plug 110 c. With the intermediate wiper plug 110 b separated from the first wiper plug 110 a, the fluid “F” flows through the bore of the first wiper plug 110 a to continue to push the remaining of the wiper plug assembly 106 (e.g., the intermediate wiper plug 110 b and the last wiper plug 110 c) in a downhole direction. As the intermediate wiper plug 110 b flows along the second pipe 404, the intermediate wiper plug 110 b wipes the second pipe 404 and pushes the cement in the second pipe 404 toward the outlet 115 of the casing 104.

As shown in FIG. 6 , the last wiper plug 110 c similarly detaches from the intermediate wiper plug 110 b at the second transition point 432. For example, the intermediate wiper plug 110 b together with the last wiper plug 110 c flow downhole along in the bore of the second pipe 404 until the intermediate wiper plug 110 b sits and is retained at the second transition point 432. At the second transition point 432, the last wiper plug 110 c detaches, under fluidic pressure applied on the first wiper plug, from the intermediate wiper plug 110 b. The first wiper plug 110 c is released from the intermediate wiper plug 110 b when the joint (e.g., the shear pin of the joint) is broken under fluid pressure of the fluid “F.”

As shown in FIG. 7 , with the intermediate wiper plug 110 b separated from the first wiper plug 110 a, the fluid “F” flows through the bore of the intermediate wiper plug 110 b to continue to push the last wiper plug 110 c in a downhole direction. As the last wiper plug 110 c flows along the last pipe 406, the last wiper plug 110 c wipes the last pipe 406 and pushes the last portion of the cement “C” in the last pipe 404 toward the outlet 115 of the casing 104 and into the annulus 112. The outlet 115 of the last pipe 406 can have a sit or inwardly-projecting shoulder that stops and retains the last wiper plug 110 c. In the last pipe 406, the last wiper plug 110 c pushes the cement “C” as the wiper plug fluidly isolates or separates the last portion of the cement in the casing from the fluid “F” uphole of the last wiper plug 110 c.

In some implementations, the wipers are sized such that only the first wiper plug 110 a wipes the first pipe 402, only the intermediate wiper plug j 110 b wipes the second pipe 404, and only the last wiper plug 110 c wipes the last pipe 406.

FIGS. 8A and 8B show schematic views of sequential steps of a wiper plug 510 being retained at a transition point 530. For example, the wiper plug 510 can have a narrow portion 540 and a wide portion 542. The wide portion 542 has an outer diameter smaller than the inner diameter of the first pipe 502 (and larger than an inner diameter of the second pipe 504) and the narrow portion 540 can have a smaller diameter than the wide portion that allows the narrow portion 540 to enter the second pipe 504. The wide portion 542 sits on the inlet of the second pipe 504. The wide portion 542 can have the annular wipers of the wiper plug 510.

FIG. 9 shows a flow chart of an example method 900 of cementing a casing in a wellbore in one trip. The method includes lowering the casing in the wellbore. The casing includes multiple pipes of progressively smaller diameters (905). The casing includes a transition point where a first pipe of the multiple pipes overlaps a second pipe of the multiple pipes that extends beyond the first pipe. The first pipe defines a first inner diameter and the second pipe that is carried by the first pipe defines a second inner diameter smaller than the first inner diameter. The method also includes flowing cement into the casing (910). The method also includes deploying, by fluidic pressure of a fluid, a wiper plug assembly in the casing upstream of the cement to push downhole the cement with the wiper plug assembly (915). The wiper plug assembly includes i) a hollow wiper plug that allows the fluid to flow across the hollow wiper plug and ii) a solid wiper plug releasably coupled to the hollow wiper plug and configured to fluidly separate the cement from the fluid. The deploying includes applying fluidic pressure until the hollow wiper plug reaches and is retained at the transition point and the solid wiper plug is released, under fluidic pressure, from the hollow wiper plug to flow downhole in the casing to a downhole end of the casing and push the cement out of the casing.

FIG. 10 shows a flow chart of an example method 1000 of cementing a wellbore. The method includes flowing cement into a casing (1005). The casing is disposed within a wellbore and has a first pipe and a second pipe carried by and extending downhole from the first pipe. The first pipe defines a first inner diameter and the second pipe defines a second inner diameter smaller than the first inner diameter. The method also includes deploying, under fluidic pressure of a fluid, a wiper plug assembly in the casing to cement the casing in one trip (1010). The wiper plug assembly is upstream of the cement to push the cement out of the casing. The wiper plug assembly has a first wiper plug and a second wiper plug releasably coupled to the first wiper plug. The first wiper plug allows fluid to flow across the first wiper plug and the second wiper plug fluidly isolates the cement from the fluid in the casing. Deploying comprises applying fluidic pressure until the first wiper plug reaches and is retained at an inlet of the second pipe and the second wiper plug is released, under fluidic pressure, from the first wiper plug to flow downhole in the casing to a downhole end of the casing and push the cement out of the casing.

Although the following detailed description contains many specific details for purposes of illustration, it is understood that one of ordinary skill in the art will appreciate that many examples, variations and alterations to the following details are within the scope and spirit of the disclosure. Accordingly, the exemplary implementations described in the present disclosure and provided in the appended figures are set forth without any loss of generality, and without imposing limitations on the claimed implementations.

Although the present implementations have been described in detail, it should be understood that various changes, substitutions, and alterations can be made hereupon without departing from the principle and scope of the disclosure. Accordingly, the scope of the present disclosure should be determined by the following claims and their appropriate legal equivalents.

The singular forms “a”, “an” and “the” include plural referents, unless the context clearly dictates otherwise.

As used in the present disclosure and in the appended claims, the words “comprise,” “has,” and “include” and all grammatical variations thereof are each intended to have an open, non-limiting meaning that does not exclude additional elements or steps.

As used in the present disclosure, terms such as “first” and “second” are arbitrarily assigned and are merely intended to differentiate between two or more components of an apparatus. It is to be understood that the words “first” and “second” serve no other purpose and are not part of the name or description of the component, nor do they necessarily define a relative location or position of the component. Furthermore, it is to be understood that that the mere use of the term “first” and “second” does not require that there be any “third” component, although that possibility is contemplated under the scope of the present disclosure. 

What is claimed is:
 1. A method of cementing a casing in a wellbore, the method comprising: lowering the casing in the wellbore, the casing comprising a plurality of pipes of progressively smaller diameters, the casing comprising a transition point where a first pipe of the plurality of pipes overlaps a second pipe of the plurality of pipes that extends beyond the first pipe, the first pipe defining a first inner diameter and the second pipe carried by the first pipe and defining a second inner diameter smaller than the first inner diameter; flowing cement into the casing; and deploying, by fluidic pressure of a fluid, a wiper plug assembly in the casing upstream of the cement to push downhole the cement with the wiper plug assembly, the wiper plug assembly comprising i) a hollow wiper plug that allows the fluid to flow across the hollow wiper plug and ii) a solid wiper plug releasably coupled to the hollow wiper plug and configured to separate the cement from the fluid, wherein deploying comprises applying fluidic pressure until the hollow wiper plug reaches and is retained at the transition point and the solid wiper plug is released, under fluidic pressure, from the hollow wiper plug to flow downhole in the casing to a downhole end of the casing and push the cement out of the casing.
 2. The method of claim 1, wherein deploying comprises cementing the wellbore in one trip by pushing, under fluidic pressure of the fluid, a last portion of the cement out of the casing into an annulus of the wellbore as the solid wiper plug travels along a last pipe of the casing to a downhole end of the last pipe where the solid wiper plug is retained.
 3. The method of claim 2, wherein deploying comprises pushing the last portion of the cement as the solid wiper plug fluidly isolates the last portion of the cement from the fluid in the last pipe.
 4. The method of claim 3, wherein the second pipe is the last pipe of the plurality of pipes.
 5. The method of claim 1, wherein the hollow wiper plug comprises a first wiper configured to wipe the first pipe and the solid wiper plug comprises a last wiper configured to wipe a last pipe of the plurality of pipes, the method further comprises wiping, with the wiper plug assembly pushing the cement, the casing.
 6. The method of claim 5, wherein the last wiper comprises an outer diameter smaller than an outer diameter of the first wiper, and the wiping comprises wiping the first pipe with the first wiper and wiping the last pipe with the last wiper.
 7. The method of claim 1, wherein the wiper plug assembly further comprises an intermediate hollow wiper plug disposed between and releasably coupled to the hollow wiper plug and the solid wiper plug, the casing comprising a second transition point where the second pipe overlaps a third pipe of the plurality of pipes that extends beyond the second pipe, and deploying comprises applying fluidic pressure until the hollow wiper plug is retained at the transition point and the intermediate hollow wiper plug is released, with the solid wiper plug coupled to the intermediate hollow wiper plug, from the hollow wiper plug, and deploying further comprises applying fluidic pressure until the intermediate hollow wiper plug is retained at the second transition point and the solid wiper plug is released, under fluidic pressure, from the intermediate hollow wiper plug.
 8. The method of claim 1, wherein the first pipe is a surface pipe extending from or near a terranean surface of the wellbore, and lowering the casing comprises setting the first pipe on or near the terranean surface of the wellbore with the second pipe suspending from the first pipe.
 9. A method, comprising: flowing cement into a casing, the casing disposed within a wellbore and comprising a first pipe and a second pipe carried by and extending downhole from the first pipe, the first pipe defining a first inner diameter and the second pipe defining a second inner diameter smaller than the first inner diameter; and deploying, under fluidic pressure of a fluid, a wiper plug assembly in the casing and upstream of the cement to push the cement out of the casing, the wiper plug assembly comprising a first wiper plug and a second wiper plug releasably coupled to the first wiper plug, the first wiper plug configured to allow fluid to flow across the first wiper plug and the second wiper plug configured to fluidly isolate the cement from the fluid in the casing, wherein deploying comprises applying fluidic pressure until the first wiper plug reaches and is retained at an inlet of the second pipe and the second wiper plug is released, under fluidic pressure, from the first wiper plug to flow downhole in the casing to a downhole end of the casing and push the cement out of the casing.
 10. The method of claim 9, wherein deploying comprises pushing, under fluidic pressure of the fluid, a last portion of the cement out of the casing into an annulus of the wellbore as the second wiper plug travels along a last pipe of the casing to a downhole end of the last pipe where the second wiper plug is retained.
 11. The method of claim 10, wherein the first wiper plug comprises a first annular wiper configured to wipe the first pipe and the second wiper plug comprises a second annular wiper configured to wipe the last pipe, the method further comprises wiping, with the wiper plug assembly pushing the cement, the first pipe and the last pipe.
 12. The method of claim 11, wherein the second annular wiper comprises an outer diameter smaller than an outer diameter of the first annular wiper, and the wiping comprises wiping from cement the first pipe with only the first annular wiper and wiping the last pipe with only the second annular wiper.
 13. The method of claim 9, wherein the wiper plug assembly further comprises an intermediate hollow wiper plug disposed between and releasably coupled to the first wiper plug and the second wiper plug, the casing comprising a third pipe carried by and extending downhole of the second pipe, and deploying comprises applying fluidic pressure until the hollow wiper plug is retained at the inlet of the second pipe and the intermediate hollow wiper plug is released, with the second wiper plug coupled to the intermediate hollow wiper plug, from the first wiper plug, and deploying further comprises applying fluidic pressure until the intermediate hollow wiper plug is retained at an inlet of the third pipe and the second wiper plug is released, under fluidic pressure, from the intermediate hollow wiper plug.
 14. A cementing wiper plug assembly, comprising: a first wiper plug defining a bore configured to direct fluid from an inlet to an outlet of the first wiper plug; and a second wiper plug releasably coupled to the first wiper plug, the second wiper plug comprising a solid body configured to fluidly isolate, when disposed within a casing of a wellbore, a first portion of the casing downhole of the wiper plug assembly from a second portion of the casing uphole of the wiper plug assembly, the casing comprising a first pipe and a second pipe carried by and extending downhole from the first pipe, the first pipe defining a first inner diameter and the second pipe defining a second inner diameter smaller than the first inner diameter, wherein the first and second wiper plugs are configured to flow together to an inlet of the second pipe and the second wiper plug is arranged to be released, under fluidic pressure, from the first wiper plug to flow downhole in the casing to a downhole end of the casing and push cement out of the casing, with the first wiper plug retained at the inlet of the second pipe.
 15. The cementing wiper plug assembly of claim 14, wherein the solid body of the second wiper plug is configured to sit and be retained at a downhole end of a last pipe of the casing.
 16. The cementing wiper plug assembly of claim 14, wherein the second wiper plug is releasably attached, by a joint comprising a shear pin, to the first wiper plug.
 17. The cementing wiper plug assembly of claim 16, wherein one of the first wiper plug or second wiper plug comprises a first inner tube comprising an aperture and inserted into a second inner tube of the other one of the first wiper plug or second wiper plug, the second inner tube comprising a shear pin inserted, with the first wiper plug and second wiper plug attached, into the aperture of the first inner tube.
 18. The cementing wiper plug assembly of claim 14, wherein the first wiper plug comprises a first annular wiper configured to wipe the first pipe and the second wiper plug comprises a second annular wiper configured to wipe a last pipe of the casing.
 19. The cementing wiper plug assembly of claim 18, wherein the second annular wiper comprises an outer diameter smaller than an outer diameter of the first annular wiper.
 20. The cementing wiper plug assembly of claim 14, further comprising an intermediate wiper plug defining a second bore configured to direct fluid from an inlet to an outlet of the intermediate wiper plug, the intermediate wiper plug disposed between and releasably coupled to the first wiper plug and the second wiper plug, the casing comprising a third pipe carried by and extending downhole of the second pipe, wherein the cementing wiper plug assembly is configured to flow to the inlet of the second pipe and the intermediate wiper plug is arranged to be released, with the second wiper plug attached to the intermediate wiper plug, from the first wiper plug to flow downhole in the casing to an inlet of the third pipe, and the second wiper plug is arranged to be released, under fluidic pressure, from the intermediate wiper plug to flow downhole in the casing to an outlet of the casing. 